A man holds a baby at the protest at Idomeni camp on the Greek border with Macedonia.
Photograph: Marko Djurica/Reuters

Hundreds of hopeful refugees have returned to Greece’s overwhelmed Idomeni camp on the border with Macedonia after rumours that the closed frontier would be forced open.

Greek authorities are trying to evacuate an estimated 11,500 people stranded at the squalid camp after Balkan states slammed shut their borders, cutting off the migrant route to Europe.

By late Sunday morning, about 250 people of all ages had gathered by the railway tracks and the border fence, singing and shouting slogans, in a largely peaceful demonstration watched by bout 50 Greek policemen in riot gear.

A refugee stands in front of a line of Greek police near the village of Idomeni. Photograph: Marko Djurica/Reuters

“No violence, we just want to cross,” read one banner, while another said: “Freedom of movement is everybody’s right.”

The wave of new arrivals appeared to be triggered by a rumour that international journalists and Red Cross officials would help them force their way across the fence into Macedonia, a young Syrian refugee told the Athens News Agency.

“We heard today that the border will open and we came here to cross,” he said.

“They told us the Red Cross and 500 journalists from all over the world will be with us,” he said, without specifying the source.

Another young Syrian refugee said his sister, who was living in Germany, had read the same claim on the internet and alerted him.

“People have been here for a long time. I think it’s very dangerous to cross, especially for the children, but what should we do?” said 24-year-old Qasim Mosawy from Afghanistan.

Dozens of other people could be seen heading through the fields towards the Idomeni crossing.

“We are trying to step up our information campaign to the refugees. Some people, for reasons we don’t understand, are creating false hope,” said Giorgos Kyritsis, spokesman of the SOMP agency, which is coordinating Athens’ response to the refugee crisis.

A protester at the makeshift camp near the village of Idomeni. Photograph: Marko Djurica/Reuters

Using loudspeakers, Greek officials told those gathering that the crossing would remain closed, repeating the message in both Arabic and Farsi, the Athens news agency said.

Two weeks ago, hundreds of people were stopped by Macedonian troops after crossing a surging river on the border. Bypassing the regular crossing, they tried to wade through the swift-flowing water, clinging to a rope strung between the banks.

Three Afghans, including a pregnant woman, drowned. The rest were stopped by Macedonian troops and sent back to Greece, along with journalists travelling with them.

“Macedonia will not allow reopening of the Balkan route,” said Ivica Bocevski, a representative of the president, Gjorge Ivanov, after the incident.

The bottleneck has left a about 50,000 people stranded across Greece, which has stepped up efforts to evacuate Idomeni.

On Friday and Saturday, 11 buses transported about 600 refugees from Idomeni to other camps in northern Greece.